Probiotics are dietary supplements containing potentially beneficial bacteria or yeast cultures. Probiotics are intended to bolster the body's naturally occurring intestinal flora and to help natural flora to maintain and/or reestablish themselves. Probiotics are sometimes recommended by doctors and nutritionists to aid in digestion, especially if the natural flora has been destroyed through antibiotic treatments, illness, or other means.
Investigation into uses and benefits for probiotics is ongoing, but a number of benefits and therapies have been suggested. For instance, it has been suggested that certain probiotics may be useful in managing lactose intolerance. Lactic acid bacteria, common probiotics, convert lactose into lactic acid; thus their ingestion may help to break down lactose to an extent that allows lactose intolerant individuals to tolerate more lactose than otherwise possible. It has also been suggested that probiotics may be advantageous in prevention of colon cancer, since some probiotics have demonstrated anti-mutagenic effects in the lab setting, apparently due to their ability to bind with heterocyclic amines (carcinogenic substances formed in cooked meat) or by decreasing the activity of certain enzymes that generate carcinogens in the digestive system. Probiotics may also be useful in lowering cholesterol levels, presumably by breaking down bile in the gut, thus inhibiting its reabsorption (which enters the blood as cholesterol). Probiotics may also lower blood pressure and improve immune function (possibly by means of competitively inhibiting harmful bacterial growth, increasing the number of antibody-producing plasma cells, increasing or improving phagocytosis, and/or increasing the proportion of T lymphocytes and Natural Killer cells). Foods containing probiotics have also been shown or suggested to have a variety of health effects, including decreasing the incidence of respiratory tract infections and dental caries in children, reducing the incidence of peptic ulcers in adults when used in combination with standard medical treatments, prevention of acute diarrhea, reducing inflammation and hypersensitivity responses, and improving mineral absorption.
Food products and dietary supplements containing viable probiotic cultures have become increasingly popular due to the suggested health benefits associated with such products. The most common form for probiotics are dairy products and probiotic fortified foods such as yogurt and cheese.
For example, yogurt is a fermented dairy product made by adding lactic acid bacterial cultures to milk, which causes the conversion of sugars (including lactose) and other carbohydrates into lactic acid. It is this process of creating lactic acid that provides the characteristic low pH (about 4.2) and resultant sour taste of yogurt and many other fermented dairy products. To offset the natural sourness of yogurt, it can be sweetened, flavored, or packaged in containers with fruit or fruit jam. Therefore, yogurt manufacturers generally add high amounts of sugar or sugar substitutes to compensate for the sour taste, which makes the product more palatable for many consumers, but results in higher calories. Additionally, the low pH and sourness of yogurt tends to be incompatible with many “ice cream-type” flavors, including for example, vanilla, chocolate, fudge, caramel, marshmallow, nut, coconut, peanut butter, mint, fruit, dulce de leche, butter pecan, cookie dough, and the like as well as combinations thereof. Conversely, a high pH product (i.e., about 4.8 to about 6.2), which enables better tasting ice cream-type flavors, is associated with a longer shelf life of incorporated probiotic cultures. However, high pH is also associated with an increased and undesirable susceptibility to pathogenic and/or spoilage microbial growth.
Natural cheese has a different anti-microbial system. The growth of undesirable pathogenic and/or spoilage microorganisms is prevented in cheese by a combination of acid developed by the starter cultures, the salt content, and relatively low moisture. The production of other antimicrobial agents by the starter lactic cultures may further boost the antimicrobial properties of the cheese.
Thus, there is a need for a dairy product, which, like yogurt or fresh cheese, is capable of providing beneficial probiotic cultures, but which has a high pH compatible with many desirable ice cream-type and savory flavors and is capable of extending the shelf life of the product. There is a need to provide such a high pH dairy product with an anti-microbial system capable of inhibiting undesirable pathogenic and/or spoilage microbial growth without significantly reducing the viability and beneficial effect of the probiotic cultures. Further, there is a need for an anti-microbial system, which remains effective when the product is subjected to temperature abuse, and which assists in preventing undesirable gas production by heterofermentative probiotic microorganisms. The present invention provides these and other benefits, as will be apparent from the following description of embodiments of the present invention.